St. Louis is facing a significant weather change today, with a forecast of showers and possible thunderstorms in the morning, followed by more rain in the afternoon. The National Weather Service reports humidity levels at 90%, a dewpoint of 68°F, and visibility reduced to 0.75 miles due to heavy rain and mist. Current temperatures are approximately 71°F, with a high expected near 80°F later in the day. A 100% chance of precipitation is in effect.